(SportsNetwork.com) - Quarterback Matt Cassel is reportedly set to opt out of his contract with the Minnesota Vikings to become a free agent.
According to NFL.com, Cassel had a clause that allowed him to walk away from the final year of the two-year contract he signed last March.
Cassel was signed to be a backup for Christian Ponder, but wound up as the starter by Week 4 when Ponder was hurt. The Vikings also signed Josh Freeman last October and all three wound up starting games for the club that finished 5-10-1.
Overall, Cassel started six games, including the last four, and played a total of nine for the Vikings in 2013. He completed 60.2 percent of his passes for 1,807 yards with 11 touchdowns and nine interceptions.
The 31-year-old veteran spent four seasons with New England and four years with Kansas City before joining the Vikings.
Cassel completed 57.4 percent of his passes for 9,549 yards with 59 touchdowns and 44 interceptions during his four seasons in Kansas City. His 2010 campaign included 3,116 yards with 27 touchdowns and just seven picks, helping the Chiefs to a surprising AFC West title.